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<link title="Dominators" rel="Chapter" href="Dominators.html"><title>CIL API Documentation (version 1.4.0) : Dataflow.BackwardsTransfer</title>
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<center><h1>Module type <a href="type_Dataflow.BackwardsTransfer.html">Dataflow.BackwardsTransfer</a></h1></center>
<br>
<pre><span class="keyword">module type</span> BackwardsTransfer = <code class="code">sig</code> <a href="Dataflow.BackwardsTransfer.html">..</a> <code class="code">end</code></pre><hr width="100%">
<pre><span id="VALname"><span class="keyword">val</span> name</span> : <code class="type">string</code></pre><div class="info">
For debugging purposes, the name of the analysis<br>
</div>
<pre><span id="VALdebug"><span class="keyword">val</span> debug</span> : <code class="type">bool ref</code></pre><div class="info">
Whether to turn on debugging<br>
</div>
<pre><span id="TYPEt"><span class="keyword">type</span> <code class="type"></code>t</span> </pre>
<div class="info">
The type of the data we compute for each block start. In many 
 presentations of backwards data flow analysis we maintain the 
 data at the block end. This is not easy to do with JVML because 
 a block has many exceptional ends. So we maintain the data for 
 the statement start.<br>
</div>

<pre><span id="VALpretty"><span class="keyword">val</span> pretty</span> : <code class="type">unit -> <a href="Dataflow.BackwardsTransfer.html#TYPEt">t</a> -> <a href="Pretty.html#TYPEdoc">Pretty.doc</a></code></pre><div class="info">
Pretty-print the state<br>
</div>
<pre><span id="VALstmtStartData"><span class="keyword">val</span> stmtStartData</span> : <code class="type"><a href="Dataflow.BackwardsTransfer.html#TYPEt">t</a> Inthash.t</code></pre><div class="info">
For each block id, the data at the start. This data structure must be 
 initialized with the initial data for each block<br>
</div>
<pre><span id="VALfuncExitData"><span class="keyword">val</span> funcExitData</span> : <code class="type"><a href="Dataflow.BackwardsTransfer.html#TYPEt">t</a></code></pre><div class="info">
The data at function exit.  Used for statements with no successors.
      This is usually bottom, since we'll also use doStmt on Return 
      statements.<br>
</div>
<pre><span id="VALcombineStmtStartData"><span class="keyword">val</span> combineStmtStartData</span> : <code class="type"><a href="Cil.html#TYPEstmt">Cil.stmt</a> -><br>       old:<a href="Dataflow.BackwardsTransfer.html#TYPEt">t</a> -><br>       <a href="Dataflow.BackwardsTransfer.html#TYPEt">t</a> -> <a href="Dataflow.BackwardsTransfer.html#TYPEt">t</a> option</code></pre><div class="info">
When the analysis reaches the start of a block, combine the old data 
 with the one we have just computed. Return None if the combination is 
 the same as the old data, otherwise return the combination. In the 
 latter case, the predecessors of the statement are put on the working 
 list.<br>
</div>
<pre><span id="VALcombineSuccessors"><span class="keyword">val</span> combineSuccessors</span> : <code class="type"><a href="Dataflow.BackwardsTransfer.html#TYPEt">t</a> -><br>       <a href="Dataflow.BackwardsTransfer.html#TYPEt">t</a> -> <a href="Dataflow.BackwardsTransfer.html#TYPEt">t</a></code></pre><div class="info">
Take the data from two successors and combine it<br>
</div>
<pre><span id="VALdoStmt"><span class="keyword">val</span> doStmt</span> : <code class="type"><a href="Cil.html#TYPEstmt">Cil.stmt</a> -> <a href="Dataflow.BackwardsTransfer.html#TYPEt">t</a> <a href="Dataflow.html#TYPEaction">Dataflow.action</a></code></pre><div class="info">
The (backwards) transfer function for a branch. The <a href="Cil.html#VALcurrentLoc"><code class="code">Cil.currentLoc</code></a> is 
 set before calling this. If it returns None, then we have some default 
 handling. Otherwise, the returned data is the data before the branch 
 (not considering the exception handlers)<br>
</div>
<pre><span id="VALdoInstr"><span class="keyword">val</span> doInstr</span> : <code class="type"><a href="Cil.html#TYPEinstr">Cil.instr</a> -><br>       <a href="Dataflow.BackwardsTransfer.html#TYPEt">t</a> -> <a href="Dataflow.BackwardsTransfer.html#TYPEt">t</a> <a href="Dataflow.html#TYPEaction">Dataflow.action</a></code></pre><div class="info">
The (backwards) transfer function for an instruction. The 
 <a href="Cil.html#VALcurrentLoc"><code class="code">Cil.currentLoc</code></a> is set before calling this. If it returns None, then we 
 have some default handling. Otherwise, the returned data is the data 
 before the branch (not considering the exception handlers)<br>
</div>
<pre><span id="VALfilterStmt"><span class="keyword">val</span> filterStmt</span> : <code class="type"><a href="Cil.html#TYPEstmt">Cil.stmt</a> -> <a href="Cil.html#TYPEstmt">Cil.stmt</a> -> bool</code></pre><div class="info">
Whether to put this predecessor block in the worklist. We give the 
 predecessor and the block whose predecessor we are (and whose data has 
 changed)<br>
</div>
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